1. Field of the Invention
This invention relates a device for and a method of recording and reproducing information on and from recording media, and more particularly to a device and method suitable for recording information and reproducing the same by a VDR (Video Disk Recorder) using a rewritable disk-shaped recording medium (hereinafter referred to as "optical video disk").
2. Description of the Prior Art
As a recording medium used for recording image information, there is generally known a tape-type recording medium such as a video tape, a semiconductor image memory such as a frame memory or a field memory, and a disk-type recording medium such as an optical video disk. These recording media are broadly used by general consumers, or for business use, etc.
In a broadcasting business at a broadcasting station there frequently occurs a case where a certain scene is required to be broadcasted again in an on-the-spot telecast for a sport event, etc. For example, in a broadcasting of a professional baseball game, a scene of home-run hit or a scene of fine play is frequently required to be again reproduced in a slow reproduction mode.
In this case, conventionally, an one-the-scene picture is recorded on a video tape while it is simultaneously broadcasted, and the video tape is rewound and reproduced when it is required.
On the other hand, in a case where a relay broadcasting is carried out over a nationwide network connecting plural local broadcasting stations with a key station at the center of the network, time allocation of broadcasting becomes frequently different between the key station and each local station. In this case, programs transmitted from the key station are not necessarily broadcasted in the local station according to the same time table for the program as that of the key station. In such a case, the local station omits a part of picture to be broadcasted, or a part of recorded pictures is broadcasted in place of some unimportant scenes. A video tape is frequently used for the recording of the pictures in such a case. The semiconductor image memory has a problem in recording capacity, and it requires a large memory capacity, so that the device becomes complicated and its cost becomes high. Therefore, it is difficult to adopt the semiconductor image memory.
As described above, the video tape which is excellently suitable for a long-term recording has been mainly used as a recording medium. However, it requires a long time for a searching operation including a tape rewinding operation, especially when a certain picture should be searched at high speed, because it is a linear recording medium.